Novel Pyrazole-Based Transition Metal Complexes: Spectral,Photophysical, Thermal and Biological Studies

A novel bioactive Schiff base (HL) named 3-methyl-1-phenyl-5-((5-nitrosalicylidene)amino)pyrazole was prepared by condensing 5-amino-3-methyl-1-phenylpyrazole with 5-nitrosalicyldehyde in methanol on a heating mantle in refluxing condition for 1 h. Some transition metal complexes of the ligand in (1 : 1) and (1 : 2) have also been prepared by condensing the metal acetate salt with the synthesized Schiff base. The Schiff base and metal complexes were characterized by different physiochemical techniques, i. e., ¹H-NMR, InfraRed, mass spectroscopy, elemental analysis, Ultraviolet-Visible, Cyclic voltammetry, electronic spectra and Electron spin resonance. The presence of water molecules in the complexes have been calculated with the help of thermogravimetric analysis. Kinetic parameters such that entropy change, enthalpy change and activation energy have been calculated with the help of Coats-Redfern equations. Fluorescence spectra showed enhancement in the fluorescence signal of the metal complexes. Square planar geometry for the copper complexes and octahedral geometry for the other metal complexes have been proposed with help of various methods. Biological activities of all the compounds have been carried out and the results disclosed that the metal complexes have high biological activity than the Schiff base having MIC value in the range 25–3.12 μg/mL and mycelial growth inhibition 60.82–96.98 %.     

Use of dynamic mechanical analysis (DMA) to determine critical transition temperatures in frozen biomaterials intended for lyophilization

Dynamic mechanical analysis is widely used to determine glass transitions in solid state materials. However, here we demonstrate the application of DMA for the determination of glass transitions (Tg’) in the frozen liquid state by means of a steel sample pocket. The use of the pocket allows frozen material to be analysed and glass transition events demonstrated. In addition, it allows weak glass transitions to be detected clearly in some complex formulations where they can be obscured by eutectic and other strong thermal events when other methods such as DSC or DTA are used. Classical excipients (trehalose, lactose, dextran) were analysed and shown to give reproducible Tg’ values, though with values slightly higher than those obtained by DSC. Finally, several complex real biological materials, typical of those encountered when freeze drying biological and biopharmaceutical materials, were analysed and the potential value of DMA demonstrated to determine the relevant glass transition temperatures for use in cryobiology and freeze drying.     

Development of Notophthalmus viridescens embryos

Although the North American, adult, red-spotted newt has been an excellent model in the study of appendage regeneration at the tissue and cell levels, experiments involving embryonic forms have been essentially impossible to perform at the molecular level due to the great difficulty in breeding newts in the laboratory. Recently, we reported our methods to successfully spawn many thousands of embryos of Notophthalmus viridescens for developmental studies on a year round basis. As no detailed examination of embryogenesis of this amphibian exists, we provide a scanning electron microscopic overview of N. viridescens development. Furthermore, we chronicle the life cycle of the newt, when produced under laboratory conditions, which also undergoes two metamorphoses as newts in the wild.     

Juglone promotes shooting and inhibits rooting in leaf explants of in vitro raised tomato (Solanum lycopersicum L. var. Pusa Ruby) seedlings

In Vitro Cellular & Developmental Biology - Plant - Juglone is an inhibitor of choline acetyltransferase, an enzyme that catalyzes the synthesis of acetylcholine. Previous works have shown the...     

Optimization and characterization of sertaconazole nitrate flexisomes embedded in hydrogel for improved antifungal activity

The aim of the present research work was to develop, characterize and optimize sertaconazole nitrate (STZN) embedded flexisomes (STZN-FS) to improve the cutaneous anti-fungal activity of STZN. Flexisomes are self-aggregating, flexible, deformable lipidic vesicles possessing an aqueous core. A 3² factorial design was implemented to optimize the effects of the critical material attributes of concentration of phospholipid (X₁) and edge activator (X₂) on the critical quality attributes of particle size (Y₁), entrapment efficiency (Y₂), and deformability index (Y₃). Statistical analysis was performed to be identify the best fit model and determine its significance. The sizes of the optimized STZN-FS were found to be 246.2?±?2.49?nm with entrapment efficiencies of 86.16?±?0.56% and deformability indices of 30.46?±?0.41. Zeta potential analysis showed negatively charged surface with a zeta potential value of ?30.9?mV. TEM analysis showed spherical shapes, confirming the vesicular characteristics. The optimized STZN-FS were further formulated into hydrogels. The % drug diffusion of STZN-FS hydrogels was found to be 13.24% and drug deposition in the skin layers was found to be 83.54%, showing that a high concentration of the drug was available at the site of action. The zone of inhibition STZN-FS hydrogel (30?mm) was higher than the marketed formulation (22?mm) and the plain STZN hydrogel (14?mm) against Candida albicans. From the above studies, it was concluded that STZN loaded STZN-FS shows high flexibility and enhanced antifungal activity. STZN-FS are thus found to be potential carriers for drug deposition in skin layers without disturbing their integrity.     

An investigation into the internal and external variables acting on crystallinity index using Fourier Transform Infrared Spectroscopy on unaltered and burned bone

The Crystallinity Index is a measure of structural order in bone and is potentially an extremely useful tool in bioarchaeology since it can assist in sequencing bones into chronological and/or stratigraphic order, act as an indicator for preservation, and assist in reconstructing burning events. Unfortunately, concerns over influencing variables and bone sampling issues inhibit full and wide-spread adoption of this approach. An attempt has been made to determine the influence of a number of internal and external variables on bone crystallinity changes. CI, C/P and C/C were calculated using Fourier Transform Infrared Spectroscopy – Attenuated Total Reflectance (FTIR-ATR) on modern burned and unburned faunal bone. Samples were taken systematically across bone elements and on the internal and external surfaces. The CI results support previous work and show increases with burning intensity. It is also shown that extrinsic variables (such as temperature and duration of burning) have more of a significant influence on CI values than intrinsic variables (such as location of sample site on the bone). A sampling strategy is suggested for those wishing to use the CI on bone in archaeological contexts.     

Genome editing of human pluripotent stem cells to generate human cellular disease models

Disease modeling with human pluripotent stem cells has come into the public spotlight with the awarding of the Nobel Prize in Physiology or Medicine for 2012 to Drs John Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent. This discovery has opened the door for the generation of pluripotent stem cells from individuals with disease and the differentiation of these cells into somatic cell types for the study of disease pathophysiology. The emergence of genome-editing technology over the past few years has made it feasible to generate and investigate human cellular disease models with even greater speed and efficiency. Here, recent technological advances in genome editing, and its utility in human biology and disease studies, are reviewed.